The invention relates to a support jack, in particular, for supporting semitrailers, said support jack comprising a vertically telescopically displaceable supporting element having an outer sleeve and an inner sleeve, each sleeve having a rectangular cross-section with four sidewalls. The invention also relates to an arrangement of a support jack on a vehicle.
Such support jacks are used especially for supporting the semitrailers of a semitrailer truck. These support jacks are manufactured from square pipes, which are inserted into each other in the manner disclosed by way of example in EP 1 104 369 B1 or EP 0 513 973 B1.
The use of support jacks involves the necessity of ensuring a bending stiffness that is required depending on the load. This is achieved by providing the square pipes with appropriate wall thickness or appropriately large cross-sectional dimensions.
Another measure known from the prior art and taken for improving the bending stiffness is to provide a third sleeve, namely a stiffening sleeve, in the inner sleeve. This considerably reduces the interior of the support jack and increases the overall weight.
It is the object of the invention to provide a support jack, which dispenses with additional stiffening sleeves and has at least the same bending stiffness as conventional support jacks. It is also an object of the present invention to specify a bend-resistant arrangement of a support jack on a vehicle.